Subtract.
Answer: First, let's start at ${20}$ on the number line. $0$ $2$ $4$ $6$ $8$ $10$ $12$ $14$ $16$ $18$ $\boxed{20}$ Next, to subtract we move left ${14}$ on the number line. $0$ $2$ $4$ $6$ $8$ $10$ $12$ $14$ $16$ $18$ $\boxed{20}$ $- 14$ The jump ends at $6$. $0$ $2$ $4$ $8$ $10$ $12$ $14$ $16$ $18$ $20$ $- 14$ $\boxed{6}$ $ {6} = {20} - {14}$